1. Field of the Invention
The present invention relates to a lens apparatus, and more particularly, to a lens apparatus including a zoom mechanism and an image stabilization mechanism, and a control method for the lens apparatus.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2000-221557 discloses a technology of correcting, in a digital video image pickup apparatus, a positional deviation of a taken image between zoom positions on a telephoto side and a wide-angle side by moving an image stabilization lens, the positional deviation occurring due to an assembling error of an image pickup element. Japanese Patent Application Laid-Open No. 2000-221557 further discloses that a positional deviation of an optical axis of an optical lens, which occurs during zooming, is also corrected by moving the image stabilization lens.
The conventional image taking apparatus has the following problems inherent therein.
As a digital camera or a video camera, there is an image taking apparatus in which a lens apparatus including optical lenses and an image pickup apparatus including an image pickup element are connected removably to each other through a mount portion of the lens apparatus and the image pickup apparatus, to thereby allow various combinations of the lens apparatus and the image pickup apparatus depending on an image taking situation. Optical axis positions of the lens apparatus and the image pickup apparatus are adjusted separately when the lens apparatus and the image pickup apparatus are assembled at the respective manufacturers, and if the same connection method for the mount portion is employed, the lens apparatus and the image pickup apparatus may be connected to each other even though the manufacturers are different. The lens apparatus and the image pickup apparatus are mounted and removed through the mount portion when an operator replaces the lens apparatus or the image pickup apparatus depending on the image taking situation, and when the operator separates the lens apparatus and the image pickup apparatus from each other for easier portability during transportation. At this time, in the lens apparatus and the image pickup apparatus which are adjusted separately, their optical axis positions may deviate from each other due to an error in adjustment or an error in precision of parts. Hence, when the lens apparatus and the image pickup apparatus are connected to each other, there may occur a positional deviation of a taken image between the telephoto side and the wide-angle side of the zoom. If a positional deviation of the optical axis further occurs during zooming in the lens apparatus due to an error in adjustment or an error in precision of parts, the positional deviations caused by different factors have occurred at two sites as a consequence. If such positional deviations occur, at a time when a zoom operation is performed on an object, there occurs a deviation of the position in a display at which the object is shown. In a case of an apparatus having an autofocus function, on the other hand, a distance measurement point and distance measurement mark of the autofocus do not match each other, resulting in a problem for the focus operation.
However, the conventional image taking apparatus cannot suppress the positional deviation occurring when the lens apparatus and the image pickup apparatus are connected to each other after shipment from the respective manufacturers. In particular, if the same connection method for the mount portion is employed, the apparatuses from the different manufacturers may be connected to each other. In this case, no information may be obtained on the respective optical axes, resulting in a problem.